Molecules of Biology Flashcards
Compound
A molecule containing different types of atoms
Element
Contains a single atom
Organic compounds contain which element?
Carbon, which can form 4 bonds with other atoms. Carbon dioxide is the only inorganic compound containing Carbon.
Polymers
Strings of repeated units
Monomer
Individual unit of a polymer
What is the monomer of a protein?
Amino acid. There are millions of possible proteins, and each have a specific amino acid sequence. Proteins contain carbon, hydrogen, oxygen, and nitrogen.
The shape of a protein determines its
Function. If the shape of a protein changes, its function changes or can no longer be carried out.
Dehydration Synthesis
Forms peptide bonds. 2 hydrogen and 1 oxygen are removed to form water. In amino acids, connection is formed at rightmost carbon.
Hydrolysis
Breaks peptide bonds. Water is added.
Amino Acid backbone structure
- NH2 is the amino group
- COOH is the carboxyl group
- The R group is the side chain that gives each amino acid its unique properties.
Carbohydrate monomer
Monosaccarides
General chemical formula for the carbohydrate
C(n)H(2n)O(n). The molecules have a 1:2:1 ratio, but as bonds form the ratio changes slightly as water is removed.
Glucose vs Fructose
Although the formula is the same, the structure is different.
Diasaccaride
Carbohydrate made by 2 monomers, like maltose and sucrose.
- Maltose is formed by 2 molecules of glucose by dehydration synthesis. C12H22O11.
- Sucrose is formed when glucose combines with fructose by dehydration synthesis. C12H22O11..
Purpose of Carbohydrates
- Quick energy, breaks into glucose, which enters blood.
- Can be converted to fat for storage, or protein to form muscle.
Polysaccaride
3 or more monosaccarides bonded together. Examples include glycogen, starch, and cellulose, which differ in the way the glucose are linked together.
- Animals store glucose as glycogen in the liver short term.
- Plants store glucose as starch
- Cellulose is the structural polysaccaride that forms the cell walls of plants.
Lipid monomers
Hydrocarbons (CH2)
Hydrophobic
Nonpolar, don’t interact with water.
Fatty acids
Long hydrocarbon chains with a carboxyl group (COOH) at one end.
Glycerol
An alcohol (-OH) with 3 carbon atoms.
3 most common forms of lipids
- Triglycerides- 3 fatty acids bonded to a glycerol molecule. Most common form in human blood, and how fat is stored.
- Phospholipids- similar in structure to triglycerides, but one fatty acid chain is replaced with a phosphate group (PO3). They are hydrophilic on phosphate end, and align their polar and nonpolar ends when they interact.
- Cholesterol- formed by rings of hydrocarbon. Found in blood tissues and blood of animals, used to maintain cell membranes and produce steroid hormones (testosterone).
Saturated lipids
Solid at room temperature, do not contain double bonds.
Lipid bilayer
In unsaturated fats, the tail spreads the molecules apart.
Steroid hormones
- 4 fused carbon rings
- Hydrophobic
Nucleic Acids
- Monomer is a nucleotide
- Found in cell nucleus
- DNA and RNA. DNA goes from DNA to RNA to proteins.
Why can’t DNA and RNA nucleotides be exchanged?
DNA uses a different sugar (deoxyribose, no oxygen) than RNA (ribose).
A nucelotide is made up of
A sugar, a phosphate, and a nitrogen base.
Which chemicals act as nucleotide bases?
- adenine, guanine, cytosine, thymine
- In RNA, thymine is replaced with uracil.
- G matches with C, A matches with T
- GC pairs are stronger, and make a DNA strand with more of these pairs more stable.
DNA structure
- A ladder that twists into a double helix
- Sugar and phosphate form the sides, while the bases form rungs.
- Each DNA strand is different due to unqiue order of nucleotides.
What is a complementary nucleic acid strand?
Complementary strands form base pairs with each other at each nucleotide.
RNA structure
- RNA is single stranded
- It can assume various shapes and form base pairs with itself.
What type of bond holds base pairs together?
Hydrogen bond
